Telescope Operational Concept

JMH: This document provides an executive summary of the overall control systems of the telescope/observatory.

The mount control system (MCS) is one of a number of sub-systems which make up the overall telescope control system (TCS). These high-level sub-systems run on Linux (CentOS) servers in the control room. The high-level telescope control software consists of a dozen sub-systems which control specific activities in the telescope and observatory. These other sub-systems include the adaptive optics system (AOS), the primary mirror cell (PMC) controls, the enclosure controls (ECS), telemetry (TEL), optical supports (OSS), etc.. Most of the sub-systems have corresponding hardware interface machines distributed around the telescope and enclosure. For example a real-time VxWorks machine controls each of the primary mirror cells, and Allen-Bradley PLCs control the enclosure, enclosure rotation and some of the telescope safety logic. Each sub-system has gigabit ethernet connections for commmand and control, for reflective memory, and for telemetry and logging. Not all TCS sub-systems have corresponding hardware systems. For example the pointing control system (PCS) which controls telescope tracking passes its trajectories on to the mount control system, and the point spread function (PSF) control system passes collimation information and active mirror figure corrections to the primary mirror cells.

As a whole, the Telescope Control System (TCS) acts as a server to the client which is the Instrument. All sequencing of observations is done by the instrument software which sends specific requests to the TCS via the Instrument Interface (IIF). The IIF then converts these requests (e.g. preset the telescope to a new field) to specific commands to the other sub-systems.

Gory Details

If you want to read about the gory details, the following links lead to manuals for the various sub-systems.

Adaptive Optics System (AOS)

• AOS - The Complete Guide (481f341a - July 2009)

Enclosure Control System (ECS)

• Enclosure Control Description (309m001d - July 2004)
• Enclosure Rotation Controller - User Manual (483s513a - March 2009)

Guiding Control System (GCS)

• Running GCS from the command line

Instrument Interface and Command Sequencer (IIF)

• C++ Instrument Interface Control Document (481s011k - July 2010)

Mount Control System (MCS and MCSPU)

• MCSPU Manual (483s199g - 21 April 2010)

Optical Support System (OSS)

• Running OSS

Pointing Control System (PCS)

• Running PCS from the command line

Point Spread Function (PSF)

• Running PSF
• Escaping from Primary Mirror Collimation Limits
• PSF User's Manual (481s062a - April 2007 {slightly behind the actual PSF})
• By Eye Active Optics
• Active Optics Modes

Primary Mirror Cells (PMC)

• PMC Software User's Manual (481s042j - February 2008)
• PMC Software Reference Manual (481s041k - February 2008)
• PMC Thermal System Description (481s045a - July 2006)

-- JohnHill - 22 Oct 2010